[Content editor]The edit button is not working if there is only a draft version of a document

Short description

After the introduction of the Save as draft feature, the edit button is not working if there is only a draft version of a document.

Steps to reproduce:

1. Go to the Content perspective
2. Create a new document
3. Select Keep draft option
4. Press the Edit button

Expected result:

The edit button should not be there when only a draft version of a document exists. 

Actual result:

Pressing the edit button does not do anything